Wildcard.md

Wildcard Swift Pattern

Wildcard pattern matches and ignores the assigned value. It helps in a number of situations where we don't care about the matched values.

Consider the following example:

_ = function(param: 5)

We may use this pattern to silence the warning raised by Xcode, in cases when we don't know yet where to use the returned value.

for _ in 0...10 {
    function()
}

In other cases we may not need to assing the current value in for in loop, we just want to iterate a number of times.

if let _ = optionalFunction() {
    print("Function passed the optional unwrapping")
}

Finally we may more Swiftly check whether the function returns non-nil value.